Factual error: The Royal Navy sailors are shown with just 'HMS' on their cap tallies. This was only seen in the Second World War for security reasons. In peacetime, the tally bears the name of the ship or shore establishment to which the rating is assigned.
Factual error: There are two Marines posted at Marine 1, the Presidential helicopter. Their pants are ridiculously long and not the image of Marines with well-fitted uniforms. Their position of attention is wrong, with the hands clenched and placed on their thighs as opposed to being fixed at the sides. Worse, when they saluted with their right hands were above the service cap brim, instead of the fingertips touching the bottom of the brim.
Protect Her - S1-E1
Factual error: When Jules and Hannah are talking about the financial shenanigans at Owen's firm, Jules says that the owner of Owen's company had fraudulently driven up the price of the stock before the IPO. This is impossible. The IPO is the first time the shares become tradeable.
Factual error: S2 E3 Along Came a Spider - Captain Carrillo is target shooting with a hand weapon. She empties the magazine, but she catches the magazine and hands it to her ranger partner instead of letting the empty magazine fall to the ground. As a trained military officer and training with special operators, catching an empty magazine is an extremely bad habit and practice, which is a big no-no. (00:40:23)